Conveyor roll

ABSTRACT

Improved conveyor roll structure for retaining thereon advancing elongated work pieces such as steel rods, bars, or the like wherein the roll exhibits a first retaining surface of revolution inclined at an angle less than 45* to the axis of the roll and a second inclined retaining surface of revolution meeting the first at an angle greater than 90* and inclined from the roll axis at an angle of less than 45*, the second surface of revolution having a depression therein whereby the cross section of said second surface presents a generally concave aspect and the second surface extends outwardly from the juncture of the first and second surfaces a predetermined distance such that the longitudinal centroid of the conveyed work piece may be contained within the vertical extent of the first and second retaining surfaces while being advanced across a plurality of rolls comprising the conveyor.

United States Patent [151 3,677,394 51 July 18, 1972 Bloom 1 1 CONVEYORROLL [72] inventor: William M. Bloom, Pittsburgh, Pa. [73] Assignee:Allegheny Ludlnln [M lnc., Pittsburgh, Pa.

[22] Filed: April 20, 1970 [21] Appl.No.: 29,918

[52] U.S. Cl. ..198/127, 29/121 R [51] lnLCl...... 15/110,B21b31l08,B6$g13/02 [58] Fleldolsearch ..29/l10,124,12$, 127-130, 29/122, 121;198/127, 33, 192, 29, 103, 104

[$6] Relerencea Cited UNITED STATES PATENTS 2,335,594 11/1943 Kerr..29/l2lA Primary Examiner-Richard E. Aegcrter AnomeyRichard A. Speer,Vincent G. Gioia and Howard R. Berkenstock. Jr.

[57} ABSTRACT Improved conveyor roll structure for retaining thereonadvancing elongated work pieces such as steel rods, bars, or the likewherein the roll exhibits a first retaining surface of revolutioninclined at an angle less than 45 to the axis of the roll and a secondinclined retaining surface of revolution meeting the first at an anglegreater than 90 and inclined from the roll axis at an angle of lea than45', the second surface of revolution having a depresion therein wherebythe cross section of said second surface presents a generally concaveaspect and the second surface extends outwardly from the juncture of thefirst and second surfaces a predetermined distance such that thelongitudinal centroid of the conveyed work piece may be contained withinthe vertical extent of the first and second retaining surfaces whilebeing advanced across a plurality of rolls comprising the conveyor.

SClalngSDrawingFigures FIG.

Patented July 18, 1972 3,677,394

2 Sheets-Sheet l IN VEN TOR.

WILL/AM M. BL 00M WFZM A Horney Patented July 18, 1972 3,677,394

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FIG. 4.

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BACKGROUND OF THE INVENTION This invention relates generally to rollsutilized in conveyor lines and particularly to rolls installed in theline where their centerlines are skewed from the perpendicular of theconveyor line. Such a line may be installed through an annealing furnacein which rods and bars of round, square, and rectangular shapes are heattreated. Conventionally, annealed bars of round, square, and hexagonalcross sections varying from five-eighths of an inch to 4 inches indiameter and from oneeighth of an inch to 4 inches thick and up to 4inches wide for rectangular cross sections may be treated in such afurnace by being heated to approximately 2,200 F. while being conveyedthrough the furnace. Immediately thereafter the workpieces areconventionally fast quenched as they exit the annealing furnace. Usuallythe quenching is accomplished with the annealed pieces traveling througha round quench ring from which the workpiece is sprayed from all aspectsby the quenching liquid exiting the ring. Those familiar with the artwill recognize that pieces exiting an annealing furnace going throughsuch stationary quench rings must be relatively straight and alignedwith the center of the ring in order to be quenched throughout at aneven rate thereby minimin'ng distortion that would otherwise result.Some prior conveyor systems having aligned rolls have employed generalV-shaped grooves on the roll surfaces to assure the alignment ofmaterial passing therethrough and a few of these conveyors have utilizedslightly skewed rolls but only for the conveying of bars of a roundcross section. There exists a need in the conveyor art for a roll shapecapable of conveying workpieces of a variety of cross sections such assquares, rounds, rectangles, etc. without particular adaptation foreach. There is a further need for a roll shape which will preserve theinitial straightness of the bar entering the furnace as well asproviding a straightening function to those non-straight bars which arecharged into the annealing furnace. The roll structure of my inventionmeets the foregoing existing needs and is hereinafter described.

SUMMARY OF THE INVENTION An improvement in roll design for a conveyorhaving a plurality of such rolls for advancing elongated workpieces suchas steel rods, bars or the like through a chamber such as a furnace forheat treating of the workpieces, said roll structure having retainingmeans for guiding the workpiece through the chamber wherein theimprovement includes a first retaining surface of revolution inclined atan angle of less than 45 to the axis of the roll, a second retainingsurface of revolution meeting the first retaining surface at an angle ofgreater than 90" and inclined at an angle of less than 45 to the axis ofthe roll. Said second surface of revolution has a depression thereinwhereby the cross section thereof presents a generally concave aspect,the second surface of revolution being adapted to extend outwardly fromthe juncture of the first and second retaining surfaces a predetermineddistance whereby the longitudinal centroid of the workpieces may becontained within the extent of the first and second retaining surfaceswhile being advanced across a plurality of rolls comprising theconveyor.

DESCRIPTION OF THE DRAWINGS FIG. I is a side elevation of an improvedconveyor roll of my invention, appearing in section.

FIG. 2 is a partial view of the invention illustrated in FIG. 1.

FIG. 3 is a front elevational view of an alternative embodiment of myinvention.

FIG. 3a is a side elevational view of the embodiment of FIG. 3.

FIG. 4 is a schematic illustration of a conveyor using the rolls of theinvention, showing the manner in which they are skewed.

2 DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingsand FIG. I, in particular, reference numeral 2 indicates a roll bodyadapted at either end to be conventionally mounted in a conveyor line(not shown). In the usual conveyor installation a plurality of rollswould be mounted over the full extent of the conveyor. The preferredembodiment of the roll described herein is included in a conveyor lineextending through an annealing furnace. Rolls 2 are mounted on centerlines approximately 2 feet apart and throughout the distance of thefurnace as well as in the areas of entrance and exit thereto. Roll 2 maybe adapted with motor means (not shown) to advance a workpieceprogressively along the conveyor line.

The improved roll structure of my invention, illustrated in the figuresincludes a first retaining surface 6 being a surface of revolutioninclined at an angle A less than 45 to roll axis 8. In the embodimentillustrated herein, the retaining surface 6 is contained on a sleeve 10which closely fits over roll body 2 and is secured thereto byconventional means such as keys 12. Further contained on roll body 2 issecond retaining surface 14, also a surface of revolution and centeredabout roll axis 8. Second retaining surface 14 may also be contained onsleeve 16 as illustrated in the described embodiment, and securedconventionally to roll body 2. In the invention retaining surface 14exhibits a varying slope to roll axis 8. In the illustrated embodimentthe surface 14 is broken into two surfaces 17 and I8. The initial slopeof surface [4 lies in surface I7 forming an initial slope at angle B.Surface 14 exhibits a second slope at angle C and lies in surface 18.The slope of surface [8 measured by angle C is greater than the slope ofsurface I7 measured at angle B, however, both are inclined to roll axis8 at angles of less than 45. In the embodiment disclosed, surface 14 isa surface of revolution of a compound line extending from the juncture20, of surfaces 6 and I4 to point 22, a predetermined distance fromjuncture 20 and further to point 24, a predetermined distancefromjuncture 20.

In the illustrated embodiment adapted to convey steel rods and bars ofA.I.S.I. 300 series alloy through an annealing furnace heated to atemperature of approximately 2,200 E, angle A is approximately 38, angleB, approximately 40, and angle C, approximately 43. Surface 6 extends alength of 2% inches from juncture 20. Surface 17, reaching from juncture20 to point 22 extends a distance of 2% inches and surface 18, reachesfrom point 22 to point 24 extending a distance of 2% inches. Thesurfaces 6, I7, and 18 are adapted for rods generally five-eighthsinches in diameter up to 4 inches in diameter and bars rectangular incross section from oneeighth inch in thickness up to 4 inches inthickness and up to 4 inches in width.

In the preferred embodiment of the roll structure illustrated in thefigures, an additional retaining surface 26 may be included being asurface of revolution from an are extending from point 24 to a verticalto roll axis 8.

As viewed in cross section in FIGS. l and 30, it may be seen that theroll structure of my invention appears generally as a V built onto theroll body 2. In the preferred embodiments each V groove consistsbasically of two surfaces (6 and 14) inclined with respect to each otherand the axis of the roll 8 upon which they are carried. The V shape isadapted for rolls which are mounted in a manner skewed from a lineextending perpendicular to the furnace longitudinal center line or passline of the conveyed material up to approximately 8". (See FIG. 4.) Theroll body 2 is skewed to cause the workpiece W to ride in the V and theretaining surfaces 6 and 14 preferably against side 14 tending to rideup the advance surface 14, which in the invention is so adapted with theincreasing slope to contain the work piece W within the V area.

As previously described, surface 14in cross section is composed of tworetaining surfaces of revolution, the first (6) being inclined at anangle of approximately 38 to roll axis 8 and the second (l4) generallybeing inclined at an angle of greater than its initial slope as atsurface 17. The total length of surface 14 is sufficiently long tocontain the maximum expected deviation from longitudinal straightness ofthe bar to be processed. in the preferred embodiment the end of theinclined surface 18 terminates in a third retaining surface 26 being anupward concave curve to further deepen the slope of the overall surface14 to increase the maximum amount of deviation from straightness ofworkpiece W which may be conveyed by the roll 2. While in the preferredembodiment the overall surface 14 in cross section appears as two flatlines 17 and 18 of different slope and a third surface 26 being aconcave curve attached thereto, the cross section of surface 14 mayexist as a long radius curve or a compound curve meeting the foregoingslope requirements.

In the charging of a non-straight workpiece W into the furnace on theskewed rolls 2 retained by surfaces 6 and 14, the bar proceeds throughthe furnace resting generally upon surface I as it is conveyed bysubsequent rolls 2. As previously discussed, the skewed relationship ofthe rolls and the nonstraight characteristics of the bar W cause it toclimb up slope l4, advancing from surface 17 to surface 18 andoccasionally to surface 26. The slope of surfaces l7, l8, and 26 is suchthat the center of gravity of the advancing bar is contained within thetop edge of the surface 14 so that the bar preferably slides back downsurface 14 toward juncture 20 of surfaces 14 and 6 or flips over andrests on surface 6 primarily rather than surface 14. As the workpiece Wrides up surface 14 and to the extent that its frictional force withsurface 14 becomes insufficient to hold the bar on the slope, it slidesdown surface 14 arriving at surface 6 with an impact which contributesto the straightening of the bar W. The slightly concave aspect ofsurface 14 defined by the increasing slopes of surfaces l7, l8, and 26further contribute to this tendency of a workpiece W to first climb upthe surface 14 and then slide down to the juncture 20 with an impact.This is accomplished by causing the workpiece to ride on surface 14 asillustrated in FIG. 2 at points Pl and P2 by virtue of the depression insurface 14. It will be recognized that the frictional force betweenworkpiece W and surface 14 is continually reduced as the workpiece Wrides upwardly on surface 14 to a position approaching that indicated bythe dotted lines in FIG. 2. l have found that for a hot roll surface ofan alloy such as Supertherm, available from Abex Corporation, Elyria,Ohio, which is utilized in the preferred embodiment that a slope of 38to 40 is sufficient to generally prevent a bar climbing upwardly on aslope V if the bar is straight. The greater the degree of curvature, ornonstraightness of a bar, the greater is its tendency or ability toclimb its supporting surface 14. it will be noticed that for larger sizematerial, (e.g., that having a width of over 2% inches in theillustrated embodiment) will span both surfaces 17 and 18 when straight.

It is important to keep the difference in slope between the two surfacesl7 and 18 small to provide sufficient support for the workpiece W shouldthe workpiece be a relatively thin bar. Such minimum difference in slopebetween the two surfaces limits the tendency for deformation of the thinbar material.

Referring now to FIGS. 3 and 30, an alternative embodiment of myinvention is illustrated. if there are space limitations restricting theinstallation of a roll having a sleeve 16 with the compound retainingsurfaces previously described, the sleeve may be made elliptical inshape as at 16'. This may also be advantageous in situations whereinweight restrictions on the roll body 2 are important. It may be furtherappreciated that the multiple ellipsoid sleeves may be oriented ondifferent axes to provide a balancing of the weight about roll body 2having a plurality of such retaining surfaces.

lclaim:

I. In a conveyor, a plurality of rolls for conveying an elongatedworkpiece such as steel rods, bars, or the like through a chamber suchas a furnace for heat treating said workpieces, each of said rollshaving retaining means for guiding said workpiece through said chamberand corn risin a first retainmg surface of revolution inclined at anangle of ess than 45 to the axis of said roll; a second retainingsurface of revolution meeting said first surface at an angle of greaterthan and inclined at an angle of less than 45 to the roll axis, saidsecond surface of revolution having a depression therein, the crosssection thereof presenting a generally concave aspect, said secondsurface of revolution being adapted to extend outwardly from thejuncture of the first and second surfaces a predetermined distance sothat the longitudinal centroid of said workpiece is contained within theextent of said first and second retaining surfaces while being advancedalong said conveyor; the rolls being mounted for rotation about axeswhich are all skewed in the same direction with respect to thelongitudinal center line of a workpiece conveyed thereon.

2. A roll according to claim 1 wherein the depression in said secondsurface of revolution is defined by the revolution of a long radiuscurved line which meets said first surface of revolution and extendssuch that the chord to said curve from the juncture with said firstsurface to the termination of said curve forms an angle of greater than90 with said first surface and is inclined to said roll axis at an angleof less than 45.

3. A roll according to claim 2 wherein said second surface of revolutionis defined by the revolution of a series of long radius curved lines.

4. In a conveyor having a plurality of rolls for conveying an elongatedworkpiece such as steel rods, bars, or the like through a chamber suchas a furnace for heat treating said workpieces, an improved roll havingretaining means for guiding said workpiece through said chamber,comprising: a first retaining surface of revolution inclined at an angleof less than 45 to the axis of said roll; a second retaining surface ofrevolution meeting said first surface at an angle of greater than 90 andinclined at an angle of less than 45 to the roll axis, said secondsurface of revolution having a depression therein defined by therevolution of a line composed of two connected straight lines, saidfirst straight line meeting said first surface of revolution andinclined at an angle of less than 45 to said roll axis, said secondstraight line having a slope greater than said first straight line andinclined at an angle of less than 45 to said roll axis, the crosssection of said roll in the area of said retaining surfaces presenting agenerally concave aspect, and said second surface of revolution beingadapted to extend outwardly from the juncture of the first and secondsurfaces a predetermined distance so that the longitudinal centroid ofsaid workpiece is contained within the extent of said first and secondretaining surfaces while being advanced along said conveyor.

5. A conveyor roll according to claim 4, wherein said second retainingsurface includes a lip defined by the revolution of said line extendedsuch that said second straight line terminates in a line curving to avertical to said roll axis, the slope of said second retaining surfacebeing defined by the chord from said lip to the juncture of said secondsurface and said first surface.

t i i I! i

1. In a conveyor, a plurality of rolls for conveying an elongatedworkpiece such as steel rods, bars, or the like through a chamber suchas a furnace for heat treating said workpieces, each of said rollshaving retaining means for guiding said workpiece through said chamberand comprising a first retaining surface of revolution inclined at anangle of less than 45* to the axis of said roll; a second retainingsurface of revolution meeting said first surface at an angle of greaterthan 90* and inclined at an angle of less than 45* to the roll axis,said second surface of revolution having a depression therein, the crosssection thereof presenting a generally concave aspect, said secondsurface of revolution being adapted to extend outwardly from thejuncture of the first and second surfaces a predetermined distance sothat the longitudinal centroid of said workpiece is contained within theextent of said first and second retaining surfaces while being advancedalong said conveyor; the rolls being mounted for rotation about axeswhich are all skewed in the same direction with respect to thelongitudinal center line of a workpiece conveyed thereon.
 2. A rollaccording to claim 1 wherein the depression in said second surface ofrevolution is defined by the revolution of a long radius curved linewhich meets said first surface of revolution and extends such that thechord to said curve from the juncture with said first surface to thetermination of said curve forms an angle of greater than 90* with saidfirst surface and is inclined to said roll axis at an angle of less than45*.
 3. A roll according to claim 2 wherein said second surface ofrevolution is defined by the revolution of a series of long radiuscurved lines.
 4. In a conveyor having a plurality of rolls for conveyingan elongated workpiece such as steel rods, bars, or the like through achamber such as a furnace for heat treating said workpieces, an improvedroll having retaining means for guiding said workpiece through saidchamber, comprising: a first retaining surface of revolution inclined atan angle of less than 45* to the axis of said roll; a second retainingsurface of revolution meeting said first surface at aN angle of greaterthan 90* and inclined at an angle of less than 45* to the roll axis,said second surface of revolution having a depression therein defined bythe revolution of a line composed of two connected straight lines, saidfirst straight line meeting said first surface of revolution andinclined at an angle of less than 45* to said roll axis, said secondstraight line having a slope greater than said first straight line andinclined at an angle of less than 45* to said roll axis, the crosssection of said roll in the area of said retaining surfaces presenting agenerally concave aspect, and said second surface of revolution beingadapted to extend outwardly from the juncture of the first and secondsurfaces a predetermined distance so that the longitudinal centroid ofsaid workpiece is contained within the extent of said first and secondretaining surfaces while being advanced along said conveyor.
 5. Aconveyor roll according to claim 4, wherein said second retainingsurface includes a lip defined by the revolution of said line extendedsuch that said second straight line terminates in a line curving to avertical to said roll axis, the slope of said second retaining surfacebeing defined by the chord from said lip to the juncture of said secondsurface and said first surface.